Logical Decisions - Classweb

The Tradeoff::Use Alternatives to Set Range option lets you
automatically revise the ranges for the current tradeoff based on
the alternatives in the analysis. LDW reviews the alternatives to
find the one that has the most preferred level on one of the two
members in the tradeoff. Since that alternative may not have the
least preferred level on the other measure, it may not be necessary
to give up the entire range of one measure to achieve the most
preferred level of the other. This option sets each measure's least
preferred level as the best level achieved by an alternative having
the most preferred level on the other measure.
Example: Suppose measures 1 and 2 both range from 0 to 1, with
1 preferred. If alternative A = (1,0), B = (1,0.5), C = (0.25,1) then
alternatives A and B have the most preferred level for measure 1
and C has the most preferred level for measure 2. LDW will
compute measure 2's least preferred level as the best level
attained on it by alternative A or B (since they have the most
preferred level for measure 1). The best level for measure 2 is the
0.5 attained by alternative B. The least preferred level for
measure 1 is the level attained by alternative C, or 0.25. Thus the
computed ranges for measures 1 and 2 are the ranges defined by
alternatives B and C: 0.5 to 1.0 for measure 1 and 0.25 to 1.0 for
measure 2.
The Allow Free Float Option. Normally, LDW only lets you
adjust one alternative and restricts it to the outside edge of the
tradeoff assessment graph.
The Tradeoff::Allow Free Float option lets you move both A and B
around the tradeoff assessment graph without restriction.
After you select the option, you can drag both alternatives with
your mouse. You can move either alternative anywhere in the
graph but you can't move an alternative outside the graph. You
also can't move an alternative to a position where it is preferred to
the other alternative on both members.
As you move the alternatives LDW will update their levels in the
four edit boxes at the bottom of the window. You can also use
these edit boxes to directly enter levels on the two members for
the two alternatives.
The Directly Enter Tradeoff Option. The Tradeoff::Directly Enter
Tradeoff option lets you directly enter the levels for the two
alternatives that make up the tradeoff. When you select this
option, LDW will display a dialog box where you can enter the
7-30 Section 7 -- Using LDW 2: Assessing